Originally Posted by vaio-fx
Whenever I turn it on, it either turns off almost straight away or the graphics card makes a screaming noise - I never get any picture on the screen.
There is a problem with the card then.
Can you try the card in a different pc?
Did you remove any clear plastic packaging film (yours may or may not have it) that normally covers the fan?
Does the screaming appear to be fan related or capacitor related?
If it is under warranty and you can find no obvious reason for the screaming I'd say it is a faulty cap, RMA time